Hmm, well, I could do one example of the air loading, shear, bending moment, curvature, and deflection. I could even do the exact solution and a numerical integration to show how close they are.
To get into geosnooker2000's questions:
I will put together some sort of an example, but it may be a few days out.
Billski
To get into geosnooker2000's questions:
- The air load falls off toward the tips - air leaks around the end. Even a rectangular wing tends to look like it has an elliptical distribution of spanwise load. That complicates things a bit. Then if the wing is tapered or has washout either by twisting the wiing or by using a more highly cambered foil towards the tip, things get more complicated;
- The airload for the wing does carry all the way to the centerline, even when a bulky fusealge is in there. The pressures developed on the wing can not just disappear at the wing, so the pressure distribution looks elliptical all the way to the centerline, and we get our airloads from that;
- The airload summed up on the entire span is actually equal to the weight of the airplane times the g's plus whatever download the tail is making to neutral out the airplane pitching moments. If the tail is making positive lift, it does then reduce the lift needed from the wing, but you do not find much of that except in canard ships;
- In a fabric covered wing, the ribs do collect the airloads and drop that load in at the rib mounts. If you have a plywood D-tube, then the skin ends up distributing the some of the lift along the spar, with a reduced point load at each rib mount. The errors from either going smooth with an exact analytical approach or doing the wing piece-wise at the rib spacing are small, as are the errors from adding fidelity or not from how the load is collected and applied to the spar. Get into composites and we tend to either have one continuous rib (massive foam core) or very few ribs, and the lifting load is nicely spread out onto the spar;
- In all skinning approaches, skin strength and airloads end up setting how far apart we can allow ribs to get... A whole 'nother topic.
I will put together some sort of an example, but it may be a few days out.
Billski